8 Some irrational numbers
\(e\) is irrational
TODO
\(e ^2\) is irrational
TODO
TODO
TODO
\(e ^4\) is irrational
TODO
TODO
TODO
TODO
TODO
TODO
TODO
\(e^r\) is irrational for every \(r\in \mathbb {Q}\setminus \{ 0\} \).
TODO
\(\pi ^2\) is irrational.
TODO
For every odd integer \(n \ge 3\), the number
\[ A(n) := \frac{1}{\pi }\arccos \left(\frac{1}{\sqrt{n}}\right) \]
is irrational.
TODO